Cutting Sugary Drinks Does Cut Weight Gain

Action Points

Note that in one randomized study, overweight and obese adolescents who received a 1-year intervention aimed at reducing consumption of sugar-sweetened beverages had a smaller increase in BMI than a control group.

In a second study, replacement of sugar-containing beverages with noncaloric beverages, in normal weight children, reduced weight gain.

SAN ANTONIO -- Replacing sugary drinks with water or other noncaloric drinks appears to reduce the amount of weight gained by children and adolescents who regularly consumed sugar-sweetened beverages, two randomized trials affirmed.

In the first trial, mostly normal-weight children ages 5 to 12 had smaller gains in body mass index z score when randomized to drink an 8-oz. sugar-free beverage every day for 18 months instead of a similarly sized sugar-sweetened beverage (-0.13 SD units, 95% CI -0.21 to -0.05), Martijn Katan, MD, PhD, of VU University Amsterdam, reported at the Obesity Society meeting here.

In the second, reported by Cara Ebbeling, PhD, of Boston Children's Hospital, ninth and 10th graders who had water and other noncaloric beverages delivered to their homes had smaller increases in BMI immediately after the 1-year intervention (0.06 versus 0.63 kg/m2, P=0.045), but not at the 2-year follow-up, which was the primary endpoint.

Nevertheless, Ebbeling and colleagues concluded that the findings of the two studies provide "support for public health guidelines that recommend limiting consumption of sugar-sweetened beverages."

Both studies were simultaneously published in the New England Journal of Medicine.

In an editorial accompanying the papers, Sonia Caprio, MD, of Yale University, agreed that the findings supported policies to reduce intake of sugary drinks, "especially those served at low cost and in excessive portions, to attempt to reverse the increase in childhood obesity."

"Such interventions, if successful," she wrote, "may also help prevent the development of type 2 diabetes and its complications in youth."

New York City recently adopted a ban on the sale of large sizes of sugar-sweetened beverages, but such a concept is not without controversy, as some researchers believe there is insufficient evidence to support a causal link between drinking sugar-sweetened beverages, weight gain, and obesity risk.

These two trials might change that, however.

David Allison, PhD, director of the Nutrition Obesity Research Center at the University of Alabama at Birmingham, said during a debate on the issue -- held before the release of the results of the current trials -- that despite the plausibility of a cause-and-effect relationship between drinking sugary beverages and weight gain, the evidence base was lacking to show that reducing consumption of the drinks will reduce obesity.

The trial results, however, changed his mind.

"I think the New England Journal papers tip the needle a little bit," he told MedPage Today. "It’s obviously not a 180-degree turnaround, but I think they lend some support to the idea that under some circumstances reducing sugar-sweetened beverage consumption can have a weight benefit for some people."

For its part, the American Beverage Association, a trade group, remains steadfast in its belief that sugar-sweetened beverages are not behind the rise in obesity rates.

"We know, and science supports, that obesity is not uniquely caused by any single food or beverage," according to a statement from the association. "Thus, studies and opinion pieces that focus solely on sugar-sweetened beverages, or any other single source of calories, do nothing meaningful to help address this serious issue."

First Trial: Drinks with 104 Calories

In the DRINK trial, Katan and colleagues set out to test whether replacing sugar-containing beverages with noncaloric drinks lessened weight gain in 641 children (mean age of 8.2) living in the Amsterdam area who said they regularly consumed sugary drinks.

The children received either one can of a sugar-free, artificially sweetened beverage with zero calories or a sugar-containing beverage with 104 calories each day for 18 months. The drinks, distributed through school, were designed to be indistinguishable from each other.

Although 26% of the children dropped out during the study, their data were imputed for the 18-month analysis.

At that time point, the BMI z score increased by 0.02 SD units in the sugar-free group and by 0.15 SD units in the sugar group, a significant difference.

The children in the sugar-free group also had smaller gains in weight, skinfold-thickness measurements, waist-to-height ratio, and fat mass.

Measurements of height and weight were available at 18 months for some of the children who had dropped out of the study, and when those data were combined with those from the children who completed the study, the difference in the change in BMI z score was no longer statistically significant between the two groups. That is probably because the children who dropped out went back to drinking sugary beverages, according to the researchers.

Katan and colleagues noted in their paper that children in the U.S. consume nearly three times as many calories from sugary drinks as were given in the trial, on average.

"We speculate that decreased consumption of such beverages might reduce the high prevalence of overweight in these children," they wrote.

Second Trial: 12 Ounces a Day

Ebbeling and colleagues tested a similar strategy of replacing consumption of sugar-sweetened beverages by delivering bottled water and other noncaloric drinks to the homes of 224 overweight and obese adolescents (mean age 15) who drank at least 12 ounces per day of sugary drinks or 100% fruit juice.

The intervention, which also included monthly phone calls with parents, three check-in visits with the participants, and written instructions to avoid sugary beverages, lasted for 1 year, and the participants were followed for 2 years.

The control participants received supermarket gift cards for retention, but no additional instruction.

The study was limited to overweight and obese adolescents after a previous pilot trial in participants across the range of weights showed that substituting noncaloric drinks for sugary beverages reduced weight gain in those with elevated BMIs, but not in the overall study population.

At baseline, both groups reported drinking 1.7 servings of sugary beverages per day. Consumption dropped in both groups during the study but was lower in the intervention group than in the control group at both 1 year (0.2 versus 0.9) and 2 years (0.4 versus 0.8).

The primary outcome was the change in BMI at 2 years, which was not significantly different between the two groups (P=0.46) despite a significant difference at 1 year. Ebbeling and colleagues noted that the lack of an effect at 2 years could be related to increasing energy intake and sugar-sweetened beverage intake after the intervention ended at 1 year or from declining intake of sugary drinks and fruit juice in the control group.

Ethnicity appeared to influence the findings. Among Hispanics – but not non-Hispanics -- the intervention was associated with less change in BMI both at 1 year and 2 years.

However, the researchers urged caution in interpreting that finding because of the small number of Hispanic participants.

The lack of a significant effect on the primary outcome in the study presented by Ebbeling notwithstanding, Caprio said in her editorial that the two randomized trials – in addition to another study presented at the meeting and also published in NEJM showing that sugar-sweetened beverage intake interacts significantly with the association between genetic susceptibility to obesity and BMI – "suggest that calories from sugar-sweetened beverages do matter."

"Collectively, the studies ... all support the view that restriction of the consumption of sweetened drinks will facilitate weight reduction," echoed Gerard Mullin, MD, MHS, of Johns Hopkins School of Medicine.

"These publications support the scientific rationale behind the recent actions taken by [New York City] Mayor Michael Bloomberg and the NYC Council to ban supersized soft drinks in NYC," he wrote in emailed comments to ABC News and MedPage Today. "Given the scientific evidence presented in these and other articles, restriction of high-caloric sugar-laden beverages would be one simple measure to stem the tide of the growing obesity epidemic. Low hanging fruit."

Caprio added, however, that reducing intake of sugary beverages alone will not reverse the obesity epidemic and that other efforts – for example, increasing physical activity – will be important.

This article was developed in collaboration with ABC News.

The study by Ludwig and colleagues was supported by grants from the National Institute of Diabetes and Digestive and Kidney Diseases to Ludwig and from the National Center for Research Resources to the Boston Children's Hospital General Clinical Research Center, the Harvard Catalyst Clinical and Translational Science Center, and the New Balance Foundation. The observational study was supported by grants from the National Institute of Child Health and Human Development, the CDC, and the Robert Wood Johnson Foundation.

Ludwig reported having relationships with Brigham and Women's Hospital, Culinary Institute of America, Kripalu Institute, NIH, Thrasher Foundation, and New Balance Foundation, and giving numerous invited lectures. He also receives royalties from Houghton Mifflin for being the author of a book on childhood obesity and reviews material on childhood obesity for WebMD. His co-authors reported relationships with the Institute for Community Health, the National Institute of Diabetes and Digestive and Kidney Diseases, New Balance Foundation, University of Massachusetts Medical School, Brigham and Women's Hospital, Dana Farber Cancer Institute, University of Pennsylvania, NIH, Thrasher Foundation, American Institute of Biological Sciences, National Institute of Child Health and Human Development, CDC, and Robert Wood Johnson Foundation.

The study by de Ruyter and colleagues was supported by grants from the Netherlands Organization for Health Research & Development, the Netherlands Heart Foundation, and the Royal Netherlands Academy of Arts and Sciences.

De Ruyter did not reported any disclosures aside from the funding. One of the other study authors reported receiving authorship fees from Bert Bakker/Prometheus, Wiley Publishers.

More in Meeting Coverage

MedPageToday is a trusted and reliable source for clinical and policy coverage that directly affects the lives and practices of health care professionals.

Physicians and other healthcare professionals may also receive Continuing Medical Education (CME) and Continuing Education (CE) credits at no cost for participating in MedPage Today-hosted educational activities.